menuconfig: fix NULL pointer dereference when searching a symbol

[~andy/linux] / fs / dcache.c

diff --git a/fs/dcache.c b/fs/dcache.c
index e8bc3420d63edcc28f0992217c860082fe424261..f09b9085f7d849e235a2b8d77c079de71c96f5d2 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -337,23 +337,6 @@ static void dentry_lru_del(struct dentry *dentry)
        }
 }
 
-/*
- * Remove a dentry that is unreferenced and about to be pruned
- * (unhashed and destroyed) from the LRU, and inform the file system.
- * This wrapper should be called _prior_ to unhashing a victim dentry.
- */
-static void dentry_lru_prune(struct dentry *dentry)
-{
-       if (!list_empty(&dentry->d_lru)) {
-               if (dentry->d_flags & DCACHE_OP_PRUNE)
-                       dentry->d_op->d_prune(dentry);
-
-               spin_lock(&dcache_lru_lock);
-               __dentry_lru_del(dentry);
-               spin_unlock(&dcache_lru_lock);
-       }
-}
-
 static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
 {
        spin_lock(&dcache_lru_lock);
@@ -486,11 +469,13 @@ relock:
        if (ref)
                dentry->d_count--;
        /*
-        * if dentry was on the d_lru list delete it from there.
         * inform the fs via d_prune that this dentry is about to be
         * unhashed and destroyed.
         */
-       dentry_lru_prune(dentry);
+       if (dentry->d_flags & DCACHE_OP_PRUNE)
+               dentry->d_op->d_prune(dentry);
+
+       dentry_lru_del(dentry);
        /* if it was on the hash then remove it */
        __d_drop(dentry);
        return d_kill(dentry, parent);
@@ -919,11 +904,13 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
                        struct inode *inode;
 
                        /*
-                        * remove the dentry from the lru, and inform
-                        * the fs that this dentry is about to be
+                        * inform the fs that this dentry is about to be
                         * unhashed and destroyed.
                         */
-                       dentry_lru_prune(dentry);
+                       if (dentry->d_flags & DCACHE_OP_PRUNE)
+                               dentry->d_op->d_prune(dentry);
+
+                       dentry_lru_del(dentry);
                        __d_shrink(dentry);
 
                        if (dentry->d_count != 0) {
@@ -1230,8 +1217,10 @@ void shrink_dcache_parent(struct dentry * parent)
        LIST_HEAD(dispose);
        int found;
 
-       while ((found = select_parent(parent, &dispose)) != 0)
+       while ((found = select_parent(parent, &dispose)) != 0) {
                shrink_dentry_list(&dispose);
+               cond_resched();
+       }
 }
 EXPORT_SYMBOL(shrink_dcache_parent);
 
@@ -2408,8 +2397,7 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
        dentry->d_parent = dentry;
        list_del_init(&dentry->d_u.d_child);
        anon->d_parent = dparent;
-       list_del(&anon->d_u.d_child);
-       list_add(&anon->d_u.d_child, &dparent->d_subdirs);
+       list_move(&anon->d_u.d_child, &dparent->d_subdirs);
 
        write_seqcount_end(&dentry->d_seq);
        write_seqcount_end(&anon->d_seq);